(a) Field of the Invention
The present invention relates to an OCB (Optical Compensated Bend) mode liquid crystal display.
(b) Description of the Related Art
A typical liquid crystal display (LCD) includes an upper panel provided with a common electrode and color filters, etc., a lower panel provided with a plurality of thin film transistors (Ms) and a plurality of pixel electrodes, etc., and a liquid crystal (LC) material interposed between the panels. The pixel electrodes and the common electrode are supplied with different voltages to generate electric field changing the orientations of LC molecules, thereby controlling light transmittance to display images.
An OCB mode LCD among the LCDs has advantages in wide viewing angle and fast response and, recently, it has been actively studied for application. However, an OCB mode LCD has a problem of low contrast ratio. It is because the OCB mode LCD gives relatively high luminance in a black state in comparison with other mode LCDs, and the high luminance in the black state is caused by the difficulty in complete compensation of the wavelength dispersion of LCD using compensation films.